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Array vs List Performance in Java (#14078)

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This commit is related to the article entitled "Array vs List Performance in Java"
This commit is contained in:
Bahaa El-Din Helmy 2023-05-21 00:52:56 +03:00 committed by GitHub
parent 7c47447776
commit 7a8afbb58f
1 changed files with 14 additions and 25 deletions
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39
core-java-modules/core-java-collections-5/src/main/java/com/baeldung/arrayandlistperformance/ArrayAndArrayListPerformance.java
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@ -5,6 +5,8 @@ import org.openjdk.jmh.infra.Blackhole;
import org.openjdk.jmh.runner.options.OptionsBuilder; import org.openjdk.jmh.runner.options.OptionsBuilder;
import java.util.ArrayList; import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeUnit;
@State(Scope.Benchmark) @State(Scope.Benchmark)
@ -16,44 +18,37 @@ public class ArrayAndArrayListPerformance {
org.openjdk.jmh.runner.Runner runner = new org.openjdk.jmh.runner.Runner(new OptionsBuilder().include(ArrayAndArrayListPerformance.class.getSimpleName()).forks(1).build()); org.openjdk.jmh.runner.Runner runner = new org.openjdk.jmh.runner.Runner(new OptionsBuilder().include(ArrayAndArrayListPerformance.class.getSimpleName()).forks(1).build());
runner.run(); runner.run();
} }
public static Integer[] array = Collections.nCopies(1000000, 1).toArray(new Integer[0]);
public static ArrayList<Integer> list = new ArrayList<Integer>(
Arrays.asList(array));
@Benchmark @Benchmark
public void arrayCreation(Blackhole blackhole) { public Integer[] arrayCreation() {
int[] array = new int[1000000]; return new Integer[1000000];
blackhole.consume(array);
} }
@Benchmark @Benchmark
public void arrayListCreation(Blackhole blackhole) { public ArrayList<Integer> arrayListCreation() {
ArrayList<Integer> list = new ArrayList<>(1000000); return new ArrayList<>(1000000);
blackhole.consume(list);
} }
@Benchmark @Benchmark
public void arrayItemsSetting(Blackhole blackhole) { public Integer[] arrayItemsSetting() {
int[] array = new int[1000000];
for (int i = 0; i < 1000000; i++) { for (int i = 0; i < 1000000; i++) {
array[i] = i; array[i] = i;
} }
blackhole.consume(array); return array;
} }
@Benchmark @Benchmark
public void arrayListItemsSetting(Blackhole blackhole) { public ArrayList<Integer> arrayListItemsSetting() {
ArrayList<Integer> list = new ArrayList<>(1000000);
for (int i = 0; i < 1000000; i++) { for (int i = 0; i < 1000000; i++) {
list.add(i); list.add(i);
} }
blackhole.consume(list); return list;
} }
@Benchmark @Benchmark
public void arrayItemsRetrieval(Blackhole blackhole) { public void arrayItemsRetrieval(Blackhole blackhole) {
int[] array = new int[1000000];
for (int i = 0; i < 1000000; i++) {
array[i] = i;
}
for (int i = 0; i < 1000000; i++) { for (int i = 0; i < 1000000; i++) {
int item = array[i]; int item = array[i];
blackhole.consume(item); blackhole.consume(item);
@ -62,10 +57,6 @@ public class ArrayAndArrayListPerformance {
@Benchmark @Benchmark
public void arrayListItemsRetrieval(Blackhole blackhole) { public void arrayListItemsRetrieval(Blackhole blackhole) {
ArrayList<Integer> list = new ArrayList<>();
for (int i = 0; i < 1000000; i++) {
list.add(i);
}
for (int i = 0; i < 1000000; i++) { for (int i = 0; i < 1000000; i++) {
int item = list.get(i); int item = list.get(i);
blackhole.consume(item); blackhole.consume(item);
@ -74,14 +65,12 @@ public class ArrayAndArrayListPerformance {
@Benchmark @Benchmark
public void arrayCloning(Blackhole blackhole) { public void arrayCloning(Blackhole blackhole) {
int[] array = new int[1000000]; Integer[] newArray = array.clone();
int[] newArray = array.clone();
blackhole.consume(newArray); blackhole.consume(newArray);
} }
@Benchmark @Benchmark
public void arrayListCloning(Blackhole blackhole) { public void arrayListCloning(Blackhole blackhole) {
ArrayList<Integer> list = new ArrayList<>(1000000);
ArrayList<Integer> newList = new ArrayList<>(list); ArrayList<Integer> newList = new ArrayList<>(list);
blackhole.consume(newList); blackhole.consume(newList);
} }